144 0001055951 XXXXXXXX LIVE 0001787297 Passage BIO, Inc. 001-39231 One Commerce Square 2005 Market Street, 39th Floor Philadelphia PA 19103 267-866-0312 OrbiMed Private Investments VII, LP Stockholder Common Stock Themis Trading LLC

10 Town Square Suite 100 Chatham NJ 07928

132645 737506.20 3120295 07/21/2025 Nasdaq Stock Market Common Stock 03/03/2020 IPO Issuer N 132645 03/03/2020 N/A N OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 04/22/2025 78049 26537.00 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 04/23/2025 89328 30372.00 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 04/24/2025 68195 21822.00 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 06/24/2025 231600 81060.00 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 06/25/2025 138800 45804.00 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 06/26/2025 213257 70374.81 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 06/27/2025 11043 3754.62 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 07/07/2025 23960 11500.80 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 07/08/2025 50700 21801.00 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 07/09/2025 57106 25126.64 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 07/10/2025 127234 50893.00 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 07/15/2025 3700 25049.00 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 07/16/2025 20048 117481.28 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 07/17/2025 22188 129356.04 OrbiMed Private Investments VII, LP

601 Lexington Ave., 54th Floor New York NY 10022

Common Stock 07/18/2025 7357 41934.90 OrbiMed Capital GP VII LLC is the general partner of OrbiMed Private Investments VII, LP. OrbiMed Advisors LLC is the managing member of OrbiMed Capital GP VII LLC. All sales of securities listed on this Form 144 made prior to July 14, 2025 reflect share amounts prior to the 1-for-20 reverse stock split that was effectuated by the Issuer on July 14, 2025. 07/21/2025 /s/ Douglas Coon, Chief Compliance Officer, OrbiMed Advisors LLC, managing member of the general partner of OrbiMed Private Investments VII, LP